| Summary: | Typescript (photocopy) Thesis (PhD) -- University of Melbourne, Faculty of Science, 1985 Bibliography: leaves 329-353. Two numerical models of terrestrial ice masses are described. One, a single flowline glacier model, has been used to simulate selected European glaciers and their response to long term climatic change. The second, a three dimensional ice sheet model, has been used to simulate the evolution and behaviour of both the Antarctic Ice Sheet and the (now extinct) North American Ice Sheet. The problem, in general terms, concerns the evolution of a visco-plastic medium constrained by topography and subject to a given mass balance and boundary conditions. Attention is given to the methods adopted for solving the relevant equations and to the means of parameterising various physical processes. Accuracy is evaluated by comparison with some specific analytic solutions. Results indicate that the known advance and retreat of many European glaciers since the early 17th century may be accounted for by summer temperature changes of the order of 1�C. It is also suggested that large scale advances, comparable to those of the past, are unlikely to reoccur until well into the next century. Studies of the North American Ice Sheet indicate that, if allowance is made for albedo feedback effects, long term changes to northern hemisphere summer insolation are capable of triggering the onset of glacial and interglacial intervals. Results demonstrate patterns of growth and decay during the past 120 thousand years and these are not compared with available evidence of ice age fluctuations. Simulations of the Antarctic Ice Sheet are described which incorporate two different schemes for dealing with the grounding line and the physical processes which operate there. It is shown how West Antarctica appears relatively unstable compared with East Antarctica but that the ice sheet as a whole is more likely to be increasing, rather than decreasing in total volume.
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